English

Characterization of AGN and their hosts in the Extended Groth Strip: a multiwavelength analysis

Astrophysics 2009-11-13 v1

Abstract

We have employed a reliable technique of classification of Active Galactic Nuclei (AGN) based on the fit of well-sampled spectral energy distributions (SEDs) with a complete set of AGN and starburst galaxy templates. We have compiled ultraviolet, optical, and infrared data for a sample of 116 AGN originally selected for their X-ray and mid-infrared emissions (96 with single detections and 20 with double optical counterparts). This is the most complete compilation of multiwavelength data for such a big sample of AGN in the Extended Groth Strip (EGS). Through these SEDs, we are able to obtain highly reliable photometric redshifts and to distinguish between pure and host-dominated AGN. For the objects with unique detection we find that they can be separated into five main groups, namely: Starburst-dominated AGN (24 % of the sample), Starburst-contaminated AGN (7 %), Type-1 AGN (21 %), Type-2 AGN (24 %), and Normal galaxy hosting AGN (24 %). We find these groups concentrated at different redshifts: Type-2 AGN and Normal galaxy hosting AGN are concentrated at low redshifts, whereas Starburst-dominated AGN and Type-1 AGN show a larger span. Correlations between hard/soft X-ray and ultraviolet, optical and infrared luminosities, respectively, are reported for the first time for such a sample of AGN spanning a wide range of redshifts. For the 20 objects with double detection the percentage of Starburst-dominated AGN increases up to 48%.

Keywords

Cite

@article{arxiv.0810.1709,
  title  = {Characterization of AGN and their hosts in the Extended Groth Strip: a multiwavelength analysis},
  author = {Cristina Ramos Almeida and Jose Miguel Rodriguez Espinosa and Guillermo Barro and Jesus Gallego and Pablo G. Perez-Gonzalez},
  journal= {arXiv preprint arXiv:0810.1709},
  year   = {2009}
}

Comments

38 pages, 8 figures, 5 tables. Accepted by AJ